All known natural calcitonin peptides are similar in structure, and all contain an amino acid sequence of 32 amino acids. Salmon calcitonin, for example, has the following formula: ##STR1##
In our U.S. Pat. No. 3,926,938 we disclose the synthesis of the salmon calcitonin above referred to, and in our U.S. Pat. No. 3,929,758 we disclose improved processes by which peptides of this character may easily be prepared.